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[proxmark3-svn] / armsrc / pcf7931.c
1 #include "proxmark3.h"
2 #include "apps.h"
3 #include "lfsampling.h"
4 #include "pcf7931.h"
5 #include "string.h"
6
7 #define T0_PCF 8 //period for the pcf7931 in us
8 #define ALLOC 16
9
10 #define abs(x) ( ((x)<0) ? -(x) : (x) )
11 #define max(x,y) ( x<y ? y:x)
12
13 int DemodPCF7931(uint8_t **outBlocks) {
14
15 uint8_t bits[256] = {0x00};
16 uint8_t blocks[8][16];
17 uint8_t *dest = BigBuf_get_addr();
18
19 int GraphTraceLen = BigBuf_max_traceLen();
20 if ( GraphTraceLen > 18000 )
21 GraphTraceLen = 18000;
22
23
24 int i, j, lastval, bitidx, half_switch;
25 int clock = 64;
26 int tolerance = clock / 8;
27 int pmc, block_done;
28 int lc, warnings = 0;
29 int num_blocks = 0;
30 int lmin=128, lmax=128;
31 uint8_t dir;
32 //clear read buffer
33 BigBuf_Clear_keep_EM();
34
35 LFSetupFPGAForADC(95, true);
36 DoAcquisition_default(0, true);
37
38 lmin = 64;
39 lmax = 192;
40
41 i = 2;
42
43 /* Find first local max/min */
44 if(dest[1] > dest[0]) {
45 while(i < GraphTraceLen) {
46 if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
47 break;
48 i++;
49 }
50 dir = 0;
51 }
52 else {
53 while(i < GraphTraceLen) {
54 if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
55 break;
56 i++;
57 }
58 dir = 1;
59 }
60
61 lastval = i++;
62 half_switch = 0;
63 pmc = 0;
64 block_done = 0;
65
66 for (bitidx = 0; i < GraphTraceLen; i++)
67 {
68 if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
69 {
70 lc = i - lastval;
71 lastval = i;
72
73 // Switch depending on lc length:
74 // Tolerance is 1/8 of clock rate (arbitrary)
75 if (abs(lc-clock/4) < tolerance) {
76 // 16T0
77 if((i - pmc) == lc) { /* 16T0 was previous one */
78 /* It's a PMC ! */
79 i += (128+127+16+32+33+16)-1;
80 lastval = i;
81 pmc = 0;
82 block_done = 1;
83 }
84 else {
85 pmc = i;
86 }
87 } else if (abs(lc-clock/2) < tolerance) {
88 // 32TO
89 if((i - pmc) == lc) { /* 16T0 was previous one */
90 /* It's a PMC ! */
91 i += (128+127+16+32+33)-1;
92 lastval = i;
93 pmc = 0;
94 block_done = 1;
95 }
96 else if(half_switch == 1) {
97 bits[bitidx++] = 0;
98 half_switch = 0;
99 }
100 else
101 half_switch++;
102 } else if (abs(lc-clock) < tolerance) {
103 // 64TO
104 bits[bitidx++] = 1;
105 } else {
106 // Error
107 warnings++;
108 if (warnings > 10)
109 {
110 Dbprintf("Error: too many detection errors, aborting.");
111 return 0;
112 }
113 }
114
115 if(block_done == 1) {
116 if(bitidx == 128) {
117 for(j=0; j<16; j++) {
118 blocks[num_blocks][j] = 128*bits[j*8+7]+
119 64*bits[j*8+6]+
120 32*bits[j*8+5]+
121 16*bits[j*8+4]+
122 8*bits[j*8+3]+
123 4*bits[j*8+2]+
124 2*bits[j*8+1]+
125 bits[j*8];
126
127 }
128 num_blocks++;
129 }
130 bitidx = 0;
131 block_done = 0;
132 half_switch = 0;
133 }
134 if(i < GraphTraceLen)
135 dir =(dest[i-1] > dest[i]) ? 0 : 1;
136 }
137 if(bitidx==255)
138 bitidx=0;
139 warnings = 0;
140 if(num_blocks == 4) break;
141 }
142 memcpy(outBlocks, blocks, 16*num_blocks);
143 return num_blocks;
144 }
145
146 int IsBlock0PCF7931(uint8_t *Block) {
147 // Assume RFU means 0 :)
148 if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
149 return 1;
150 if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
151 return 1;
152 return 0;
153 }
154
155 int IsBlock1PCF7931(uint8_t *Block) {
156 // Assume RFU means 0 :)
157 if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
158 if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
159 return 1;
160
161 return 0;
162 }
163
164 void ReadPCF7931() {
165 uint8_t Blocks[8][17];
166 uint8_t tmpBlocks[4][16];
167 int i, j, ind, ind2, n;
168 int num_blocks = 0;
169 int max_blocks = 8;
170 int ident = 0;
171 int error = 0;
172 int tries = 0;
173
174 memset(Blocks, 0, 8*17*sizeof(uint8_t));
175
176 do {
177 memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
178 n = DemodPCF7931((uint8_t**)tmpBlocks);
179 if(!n)
180 error++;
181 if(error==10 && num_blocks == 0) {
182 Dbprintf("Error, no tag or bad tag");
183 return;
184 }
185 else if (tries==20 || error==10) {
186 Dbprintf("Error reading the tag");
187 Dbprintf("Here is the partial content");
188 goto end;
189 }
190
191 for(i=0; i<n; i++)
192 Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
193 tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
194 tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
195 if(!ident) {
196 for(i=0; i<n; i++) {
197 if(IsBlock0PCF7931(tmpBlocks[i])) {
198 // Found block 0 ?
199 if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
200 // Found block 1!
201 // \o/
202 ident = 1;
203 memcpy(Blocks[0], tmpBlocks[i], 16);
204 Blocks[0][ALLOC] = 1;
205 memcpy(Blocks[1], tmpBlocks[i+1], 16);
206 Blocks[1][ALLOC] = 1;
207 max_blocks = max((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
208 // Debug print
209 Dbprintf("(dbg) Max blocks: %d", max_blocks);
210 num_blocks = 2;
211 // Handle following blocks
212 for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
213 if(j==n) j=0;
214 if(j==i) break;
215 memcpy(Blocks[ind2], tmpBlocks[j], 16);
216 Blocks[ind2][ALLOC] = 1;
217 }
218 break;
219 }
220 }
221 }
222 }
223 else {
224 for(i=0; i<n; i++) { // Look for identical block in known blocks
225 if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
226 for(j=0; j<max_blocks; j++) {
227 if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
228 // Found an identical block
229 for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
230 if(ind2 < 0)
231 ind2 = max_blocks;
232 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
233 // Dbprintf("Tmp %d -> Block %d", ind, ind2);
234 memcpy(Blocks[ind2], tmpBlocks[ind], 16);
235 Blocks[ind2][ALLOC] = 1;
236 num_blocks++;
237 if(num_blocks == max_blocks) goto end;
238 }
239 }
240 for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
241 if(ind2 > max_blocks)
242 ind2 = 0;
243 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
244 // Dbprintf("Tmp %d -> Block %d", ind, ind2);
245 memcpy(Blocks[ind2], tmpBlocks[ind], 16);
246 Blocks[ind2][ALLOC] = 1;
247 num_blocks++;
248 if(num_blocks == max_blocks) goto end;
249 }
250 }
251 }
252 }
253 }
254 }
255 }
256 tries++;
257 if (BUTTON_PRESS()) return;
258 } while (num_blocks != max_blocks);
259 end:
260 Dbprintf("-----------------------------------------");
261 Dbprintf("Memory content:");
262 Dbprintf("-----------------------------------------");
263 for(i=0; i<max_blocks; i++) {
264 if(Blocks[i][ALLOC]==1)
265 Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
266 Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
267 Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
268 else
269 Dbprintf("<missing block %d>", i);
270 }
271 Dbprintf("-----------------------------------------");
272
273 cmd_send(CMD_ACK,0,0,0,0,0);
274 }
275
276
277 /* Write on a byte of a PCF7931 tag
278 * @param address : address of the block to write
279 @param byte : address of the byte to write
280 @param data : data to write
281 */
282 void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
283 {
284
285 uint32_t tab[1024]={0}; // data times frame
286 uint32_t u = 0;
287 uint8_t parity = 0;
288 bool comp = 0;
289
290 //BUILD OF THE DATA FRAME
291
292 //alimentation of the tag (time for initializing)
293 AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
294
295 //PMC
296 Dbprintf("Initialization delay : %d us", init_delay);
297 AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
298
299 Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
300
301 //password indication bit
302 AddBitPCF7931(1, tab, l, p);
303
304
305 //password (on 56 bits)
306 Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
307 AddBytePCF7931(pass1, tab, l, p);
308 AddBytePCF7931(pass2, tab, l, p);
309 AddBytePCF7931(pass3, tab, l, p);
310 AddBytePCF7931(pass4, tab, l, p);
311 AddBytePCF7931(pass5, tab, l, p);
312 AddBytePCF7931(pass6, tab, l, p);
313 AddBytePCF7931(pass7, tab, l, p);
314
315 //programming mode (0 or 1)
316 AddBitPCF7931(0, tab, l, p);
317
318 //block adress on 6 bits
319 Dbprintf("Block address : %02x", address);
320 for (u=0; u<6; u++)
321 {
322 if (address&(1<<u)) { // bit 1
323 parity++;
324 AddBitPCF7931(1, tab, l, p);
325 } else{ // bit 0
326 AddBitPCF7931(0, tab, l, p);
327 }
328 }
329
330 //byte address on 4 bits
331 Dbprintf("Byte address : %02x", byte);
332 for (u=0; u<4; u++)
333 {
334 if (byte&(1<<u)) { // bit 1
335 parity++;
336 AddBitPCF7931(1, tab, l, p);
337 } else{ // bit 0
338 AddBitPCF7931(0, tab, l, p);
339 }
340 }
341
342 //data on 8 bits
343 Dbprintf("Data : %02x", data);
344 for (u=0; u<8; u++)
345 {
346 if (data&(1<<u)) { // bit 1
347 parity++;
348 AddBitPCF7931(1, tab, l, p);
349 } else{ //bit 0
350 AddBitPCF7931(0, tab, l, p);
351 }
352 }
353
354
355 //parity bit
356 if((parity%2)==0){
357 AddBitPCF7931(0, tab, l, p); //even parity
358 }else{
359 AddBitPCF7931(1, tab, l, p);//odd parity
360 }
361
362 //time access memory
363 AddPatternPCF7931(5120+2680, 0, 0, tab);
364
365 //conversion of the scale time
366 for(u=0;u<500;u++){
367 tab[u]=(tab[u] * 3)/2;
368 }
369
370
371 //compennsation of the counter reload
372 while (!comp){
373 comp = 1;
374 for(u=0;tab[u]!=0;u++){
375 if(tab[u] > 0xFFFF){
376 tab[u] -= 0xFFFF;
377 comp = 0;
378 }
379 }
380 }
381
382 SendCmdPCF7931(tab);
383 }
384
385
386
387 /* Send a trame to a PCF7931 tags
388 * @param tab : array of the data frame
389 */
390
391 void SendCmdPCF7931(uint32_t * tab){
392 uint16_t u=0;
393 uint16_t tempo=0;
394
395 Dbprintf("SENDING DATA FRAME...");
396
397 FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
398
399 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
400
401 FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
402
403 LED_A_ON();
404
405 // steal this pin from the SSP and use it to control the modulation
406 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
407 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
408
409 //initialization of the timer
410 AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
411 AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
412 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
413 AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
414 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
415 AT91C_BASE_TCB->TCB_BCR = 1;
416
417
418 tempo = AT91C_BASE_TC0->TC_CV;
419 for(u=0;tab[u]!= 0;u+=3){
420
421
422 // modulate antenna
423 HIGH(GPIO_SSC_DOUT);
424 while(tempo != tab[u]){
425 tempo = AT91C_BASE_TC0->TC_CV;
426 }
427
428 // stop modulating antenna
429 LOW(GPIO_SSC_DOUT);
430 while(tempo != tab[u+1]){
431 tempo = AT91C_BASE_TC0->TC_CV;
432 }
433
434
435 // modulate antenna
436 HIGH(GPIO_SSC_DOUT);
437 while(tempo != tab[u+2]){
438 tempo = AT91C_BASE_TC0->TC_CV;
439 }
440
441
442 }
443
444 LED_A_OFF();
445 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
446 SpinDelay(200);
447
448
449 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
450 DbpString("FINISH !");
451 DbpString("(Could be usefull to send the same trame many times)");
452 LED(0xFFFF, 1000);
453 }
454
455
456 /* Add a byte for building the data frame of PCF7931 tags
457 * @param b : byte to add
458 * @param tab : array of the data frame
459 * @param l : offset on low pulse width
460 * @param p : offset on low pulse positioning
461 */
462
463 bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
464
465 uint32_t u;
466 for (u=0; u<8; u++)
467 {
468 if (byte&(1<<u)) { //bit à 1
469 if(AddBitPCF7931(1, tab, l, p)==1)return 1;
470 } else { //bit à 0
471 if(AddBitPCF7931(0, tab, l, p)==1)return 1;
472 }
473 }
474
475 return 0;
476 }
477
478 /* Add a bits for building the data frame of PCF7931 tags
479 * @param b : bit to add
480 * @param tab : array of the data frame
481 * @param l : offset on low pulse width
482 * @param p : offset on low pulse positioning
483 */
484 bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
485 uint8_t u = 0;
486
487 for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
488
489
490 if(b==1){ //add a bit 1
491 if(u==0) tab[u] = 34*T0_PCF+p;
492 else tab[u] = 34*T0_PCF+tab[u-1]+p;
493
494 tab[u+1] = 6*T0_PCF+tab[u]+l;
495 tab[u+2] = 88*T0_PCF+tab[u+1]-l-p;
496 return 0;
497 }else{ //add a bit 0
498
499 if(u==0) tab[u] = 98*T0_PCF+p;
500 else tab[u] = 98*T0_PCF+tab[u-1]+p;
501
502 tab[u+1] = 6*T0_PCF+tab[u]+l;
503 tab[u+2] = 24*T0_PCF+tab[u+1]-l-p;
504 return 0;
505 }
506
507
508 return 1;
509 }
510
511 /* Add a custom pattern in the data frame
512 * @param a : delay of the first high pulse
513 * @param b : delay of the low pulse
514 * @param c : delay of the last high pulse
515 * @param tab : array of the data frame
516 */
517 bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
518 uint32_t u = 0;
519 for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
520
521 if(u==0) tab[u] = a;
522 else tab[u] = a + tab[u-1];
523
524 tab[u+1] = b+tab[u];
525 tab[u+2] = c+tab[u+1];
526
527 return 0;
528 }
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